People like Lesnar & Rock are part-timers, so no point on them ending it.

Orton, Cena, and Punk have their legacy set, no point on ending it.

People like Barrett, Ziggler, and Sheamus will have to stay the rest of their career as a heel if they end it. And it's a huge doubt they can last 20+ years like Taker did. And yes, I do think anybody that ends The Streak has to last as long as or longer than The Streak, cause it will be stupid to end a 20 year old legacy only to be able to use it for 3 or 4 years.

If I had to pick, rising newcomer. The old wrestling rule of putting someone who needs it over on your way out. Also it doesn't help that two of the biggest stars in wrestling history (Flair and HBK) were both retired by established vets (HBK and Undertaker)

IMO, I think the person who ends the streak (if it happens, I don't think it should) should be a wrestler in between vet and rising newcomer. Randy Orton circa 2005 was perfect. Someone who could win the world title (or has been a world champion before) has been in the main event for a good while but isn't an automatic Hall of Fame type of guy.